The present invention is directed to a method and apparatus for changing printing members such as pressure rolls and engraved cylinders for each printing unit of a printing press.
Printing presses known heretofore generally include a feeding unit with a web unwinding arrangement and a feeding arrangement which feeding unit is then followed by several printing units each of which will print a different color according to the particular job which is to be done. For instance to produce a print having multiple colors, the press may print white in the first printing unit, the second printing unit will print a yellow color, a third unit will print red, a fourth unit will print blue and a fifth unit will print black. These printing presses are able to execute various kinds of printing and when one print is stopped another may be started; however, the order of colors in the various printing units might need to be completely changed. Sometimes, one or more units are taken out of the order. If the colors are arranged differently, the printing members or elements have to be cleaned and provided with new ink with the color of the ink being adjusted to the new job that is being started. In that case, one might use several sets of printing elements so that the operator introduced already prepared elements into the press or machine. Thus the machine keeps running while the previously used printing elements are cleaned. Of course, the machine has to be stopped while the printing elements are changed usually two elements have to be replaced these are the engraved printing cylinder and its inking device which are mounted together on a first carriage and the separate pressure roller. To remove the pressure roller from its position in the printing unit, it is first mounted on a trolley to enable it removable. The machine described hereinbefore requires the removal and replacement of the carriage supporting the engraved cylinder and the removal of the pressure rolls for each of the five printing units. This operation can last a long time and evidently requires the standstill of the printing press.